1. Field of the Invention
The present invention relates to fluid mixing valves as may be used for controlling the volume and proportioning of flow through hot and cold water faucets.
2. Description of the Art
Mixing valves for governing the volume and temperature from separate hot and cold water inlets through the manipulation of a single control handle have been the subject of extensive design and innovation. Some operate the control handle from side to side to control temperature, and forward and backward to control volume. Other designs rotate the control handle to govern temperature, and have a push-pull movement to govern volume. Internally, the valve structures may open and close hot and cold ports by sliding and rotating a cylinder, or by causing a sleeve-shaped flexible valve toward and away from inlet ports, or turning cylindrical balls, or sliding an appropriately apertured disc across inlet ports in a composite sideward and rotational movement.
A type of sliding disc valve which has gained some acceptance relies on a lever actuator mechanism in which the lever is universally mounted medially of its ends in a bearing member above the sliding disc. One end of the lever extends outwardly from the bearing to be grasped by a user, and the other end of the lever extends inwardly from the bearing into engagement with the top of the valve disc. A swinging motion of the top part of the lever pivots the lower part of the lever on the bearing, thereby moving the sliding disk over hot and cold water inlets. In order to provide the lever mounting, such valves often use pin connections between the lever arm and bearing, or use a spherical ball on the lever arm and a spherical seat for the ball. Examples of this type of valve are described in U.S. Pat. No. Re. 27,036 which issued on Jan. 19, 1971 to L. J. Miller, and U.S. Pat. No. 3,854,493 which issued on Dec. 17, 1974 to G. J. Farrell.
However, valves of this type are not without problems. They are mechanically complex and the bearings may tend to loosen and become imprecise in operation. Some valves of this type are noisy due to abrupt opening or closing of the valve. Also, other such valves will from time to time cause discomfort to users due to the inability of the user to prevent abrupt changes in temperature when adjusting temperature of the fluid.